An alternative renewable source of squalene for use in emulsion adjuvants.

Emulsions have been used to boost immunogenicity of antigens since the discovery of complete Freunds adjuvant. Optimization to reduce reactogenicity of emulsion adjuvants lead to the development of oil in water emulsions based on squalene. MF59 is an oil-in-water emulsion that is a component of an approved influenza product in Europe. Currently MF59 is manufactured from squalene derived from an animal source. Recently a high purity plant-derived squalene source has become available at an appropriate purity for a vaccine adjuvant. The purpose of this study was to evaluate and compare animal-derived squalene and plant-derived squalene for equivalency. Nanoemulsions were prepared and analyzed for size and viscosity prepared from each source. The two emulsions were administered in two separate animal studies, one focusing on Neisseria meningitidis B, and one focusing on influenza. Readouts were ELISA titers for each antigen and serum bactericidal activity for N. meningitidis B, and hemagglutinin inhibition for influenza to see the functionality of the antibodies produced. Results indicate that there are no differences between the antibodies elicited after immunization from an emulsion made with oil derived from either an animal or plant-source.